Question

When trying to generate an action potential what is the first type of gate to open? And is it a chemical or a voltage gate?

Answer 1

A rapid change in the polarity within the membrane of the axon when the transmission of the nerve impulses occurs is known as an action potential. An action potential is generated when the stimulus causes the depolarization of the axonal membrane to a certain level called a threshold.

The electrical change in the cell that results in a decrease in the negative charge inside the cell is known as depolarization. It is an important function of many cells in maintaining the physiology and proper communication within the organism.

The $Na^{+}/K^{+}$ pump generate gradients of both potassium and sodium ions and is important for the maintenance of the resting membrane potential. These gradients help to transmit the electrical signals along nerves.

At the beginning of the action potential, the gates of the $Na^{+}$ (sodium) channels open first allowing the flow of the $Na^{+}$ (sodium ions) against its concentration gradient into the axon. There is a change in the membrane potential from -65mV to +40mV when $Na^{+}$ moves inside the axon. This process is known as depolarization because the charge present inside the axonal membrane changes from negative to positive.

Therefore, the sodium channel which is a voltage-gated channel is the first type of gate to open when an action potential is generated.